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-rw-r--r--arch/arm64/kernel/stacktrace.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 684c265116..6b32588603 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -324,3 +324,123 @@ void show_stack(struct task_struct *tsk, unsigned long *sp, const char *loglvl)
dump_backtrace(NULL, tsk, loglvl);
barrier();
}
+
+/*
+ * The struct defined for userspace stack frame in AARCH64 mode.
+ */
+struct frame_tail {
+ struct frame_tail __user *fp;
+ unsigned long lr;
+} __attribute__((packed));
+
+/*
+ * Get the return address for a single stackframe and return a pointer to the
+ * next frame tail.
+ */
+static struct frame_tail __user *
+unwind_user_frame(struct frame_tail __user *tail, void *cookie,
+ stack_trace_consume_fn consume_entry)
+{
+ struct frame_tail buftail;
+ unsigned long err;
+ unsigned long lr;
+
+ /* Also check accessibility of one struct frame_tail beyond */
+ if (!access_ok(tail, sizeof(buftail)))
+ return NULL;
+
+ pagefault_disable();
+ err = __copy_from_user_inatomic(&buftail, tail, sizeof(buftail));
+ pagefault_enable();
+
+ if (err)
+ return NULL;
+
+ lr = ptrauth_strip_user_insn_pac(buftail.lr);
+
+ if (!consume_entry(cookie, lr))
+ return NULL;
+
+ /*
+ * Frame pointers should strictly progress back up the stack
+ * (towards higher addresses).
+ */
+ if (tail >= buftail.fp)
+ return NULL;
+
+ return buftail.fp;
+}
+
+#ifdef CONFIG_COMPAT
+/*
+ * The registers we're interested in are at the end of the variable
+ * length saved register structure. The fp points at the end of this
+ * structure so the address of this struct is:
+ * (struct compat_frame_tail *)(xxx->fp)-1
+ *
+ * This code has been adapted from the ARM OProfile support.
+ */
+struct compat_frame_tail {
+ compat_uptr_t fp; /* a (struct compat_frame_tail *) in compat mode */
+ u32 sp;
+ u32 lr;
+} __attribute__((packed));
+
+static struct compat_frame_tail __user *
+unwind_compat_user_frame(struct compat_frame_tail __user *tail, void *cookie,
+ stack_trace_consume_fn consume_entry)
+{
+ struct compat_frame_tail buftail;
+ unsigned long err;
+
+ /* Also check accessibility of one struct frame_tail beyond */
+ if (!access_ok(tail, sizeof(buftail)))
+ return NULL;
+
+ pagefault_disable();
+ err = __copy_from_user_inatomic(&buftail, tail, sizeof(buftail));
+ pagefault_enable();
+
+ if (err)
+ return NULL;
+
+ if (!consume_entry(cookie, buftail.lr))
+ return NULL;
+
+ /*
+ * Frame pointers should strictly progress back up the stack
+ * (towards higher addresses).
+ */
+ if (tail + 1 >= (struct compat_frame_tail __user *)
+ compat_ptr(buftail.fp))
+ return NULL;
+
+ return (struct compat_frame_tail __user *)compat_ptr(buftail.fp) - 1;
+}
+#endif /* CONFIG_COMPAT */
+
+
+void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
+ const struct pt_regs *regs)
+{
+ if (!consume_entry(cookie, regs->pc))
+ return;
+
+ if (!compat_user_mode(regs)) {
+ /* AARCH64 mode */
+ struct frame_tail __user *tail;
+
+ tail = (struct frame_tail __user *)regs->regs[29];
+ while (tail && !((unsigned long)tail & 0x7))
+ tail = unwind_user_frame(tail, cookie, consume_entry);
+ } else {
+#ifdef CONFIG_COMPAT
+ /* AARCH32 compat mode */
+ struct compat_frame_tail __user *tail;
+
+ tail = (struct compat_frame_tail __user *)regs->compat_fp - 1;
+ while (tail && !((unsigned long)tail & 0x3))
+ tail = unwind_compat_user_frame(tail, cookie, consume_entry);
+#endif
+ }
+}